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Editor · guide

Scene menus

A pie menu under the cursor and a list beside it, both filled by one registration and filtered by the active mode.

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What it is#

Two menus the viewport summons, and one registration behind both.

RadialMenu is a pie menu: wedges on a ring round the point it opened at, aimed by direction rather than by pointing. RadialItem is one wedge. Both live in Vixen.Ui.Controls and know nothing about the editor — a radial menu is a general idiom and this one is a peer of Menu and ContextMenu.

SceneMenuItem is the editor's half: a record naming a command, which of the two menus it belongs to, and — the part that matters — which mode offers it. SceneMenuSurface is that choice, and it is a flags enum because the useful case is both.

The editor binds Q to the pie and C to the list, both scoped to the scene pane.

What it is for#

A mode is a set of verbs somebody uses constantly, and doc 24's argument for modes is that a viewport cannot show them all at once. The mode bar and the tool strip are two answers to that and both cost a trip to the edge of the screen; a pie under the cursor costs a flick and does not move the eye, which is what a tool used forty times a minute needs.

⚠ A pie is fast because a given verb is always in the same direction. After a week the direction is muscle memory and the menu is not read at all. That is why nothing sorts the wedges, why Order is worth setting, and why an entry belonging to a mode is *absent* in other modes rather than greyed — a ring whose live wedges move as modes change is a ring nobody can learn.

⚠ Two gestures, and both have to work or neither is used. *Press the key, then click a wedge* is what somebody does while they are still reading the labels. *Hold the key, flick, release* is what they do afterwards. They are the same menu in the same place: the command runs on the key going down, so the menu opens held, and the release either lands on a wedge and runs it or lands in the dead zone and leaves the menu up to be clicked.

⚠ The context list is a key rather than the secondary button, and the viewport is why. Right-drag orbits and right-press begins fly navigation, which every 3D editor binds the same way and none of them gives up for a menu.

Using it#

An entry names a command id rather than carrying an action, which is the same decision the toolbar and the menu bar already made: "Extrude" is one thing whether it is reached from a menu, a pie, a shortcut or the palette, with one enablement and one binding. What a SceneMenuItem adds is *where*, not *what*.

Mode is matched against EditorModes.Active. An entry with none is offered everywhere.

Examples#

A module putting its two commonest verbs a flick away, and its whole set in the list:

csharp
public void Activate(PluginContext context) {    var registry = context.Services.Require<IEditorRegistry>();    context.Owns(registry.Add(new SceneMenuItem("blockout.extrude") { Mode = "blockout", Order = 0 }));    context.Owns(registry.Add(new SceneMenuItem("blockout.bevel") { Mode = "blockout", Order = 1 }));    // Read rather than aimed: the long tail goes in the list only.    context.Owns(        registry.Add(new SceneMenuItem("blockout.flip", SceneMenuSurface.Context) { Mode = "blockout" })    );}

Driving the control directly, for a host that is not the scene view:

csharp
var pie = document.Root.Add<RadialMenu>();pie.AddItem("Move");pie.AddItem("Rotate");pie.AddItem("Scale");pie.AddItem("Delete");pie.Chose += (_, item) => Run(item.Index);pie.OpenAt(cursor.X, cursor.Y, hold: true);

WedgeAt is what the aiming is built out of, and it is worth knowing about because it is *not* a hit test: a flick routinely overshoots the ring by a long way, so what is measured is the angle from the centre, and how far out the pointer went matters only for the dead zone.

See also#

  • Editor modes — what a mode is, and the key-conflict argument these menus finish.
  • Writing a plugin — the registration scope context.Owns puts an entry in,
  • and what withdraws it on unload.
  • EditorCommand, CommandRegistry — where the verbs themselves live.